When traveling down today it might be worth going down the M40 to Oxford services this is the junction that is after Bicester (A34), by going this way you will miss the Oxford Ringroad and will bring you to the football ground the back way. If going this way you will need to go via Wheatley then Garsington then to The football stadium (Do not go on A40 into Oxford as this will take you back on the ring road), or go via Great Milton then Stadhampton then football stadium. It takes about 20 to 25 mins generally on this route from M40. This is the way I go to Football.